Hearing device comprising an automatic power switching

ABSTRACT

According to an aspect, a hearing device such as a bone conduction hearing aid is disclosed. The device includes an implantable prosthetic system comprising a receiver coil, and an external audio processor device. The audio processor device includes a microphone configured to transform a received sound into an electrical input signal, a signal processor configured to process the electrical input signal into a processed electrical data signal, a transmitter coil configured to inductively transmit data signals and/or power, across the skin of a hearing device user, to the receiver coil. The audio processor device further includes a detection device configured to detect if the external audio processor device is within a predefined distance from the implantable prosthetic system or to detect if a coupling coefficient between the transmitter coil and a receiver coil is within a predefined value range.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending application Ser. No.15/726,829, filed on Oct. 6, 2017, which claims priority under 35 U.S.C.§ 119(a) to Application No. 16193091.2, filed in Europe on Oct. 10,2016, all of which are hereby expressly incorporated by reference intothe present application.

FIELD

The present disclosure relates to a hearing device such as animplantable transcutaneous bone conduction hearing aid comprising animplantable prosthetic system. More particularly, the disclosure relatesto a bone conduction hearing aid comprising an implantable prostheticsystem and being configured to receive its operating energy from anexternal power source using a radio frequency link.

BACKGROUND

The medical device industry produces a wide variety of electronic andmechanical devices for treating patient medical conditions. Dependingupon the medical condition, medical devices may be surgically implantedor connected externally to the patient receiving treatment.

Implantable medical devices are commonly used today to treat patientssuffering from various ailments. One type of implantable medical deviceis a bone conduction hearing aid. A bone conduction hearing aid works byconverting the sound signal into a mechanical vibratory stimulus.Heretofore, the vibrating portion of the aid (vibrator) transmits itsvibrations to the bone structure of the skull. The vibration of theskull stimulates the cochlea and a sound is perceived.

There are generally five major types of bone conduction devices,including: (1) External bone conduction devices where a vibrator is heldto the side of the head by a band that traverses around the head (2)Bone anchored hearing devices where a screw is placed through the skininto the skull and a vibrator transducer is hung to the side of thescrew (abutment) (3) Magnetic bone conduction hearing implants, wheremagnets are implanted and attached to the skull and externallypositioned magnets provide a normal force to the side of the head tohold the vibrator to the head; (4) Teeth vibrators where the vibrator isattached to a tooth or a dental implant (5) Active implantable boneconduction devices, where a transducer is implanted under the skin tovibrate the skull.

Some of these bone conduction hearing aids may be partially implantablewhere a power source is worn outside the patient's body whereas thevibrator is implanted subcutaneously, such as in the type 5 recited inthe preceding paragraph. This system requires an antenna to be placed onthe patient's skin over the site of an implanted receiver to provideenergy and control to the implanted device. Such type of hearing aidsreceive their operating energy from an external power source likebatteries using a radio frequency link, typically to avoid need forimplanted batteries. The received energy is then utilized to drive avibrator that is implanted within the patient. Typical transcutaneousbone conduction hearing aids of today, however, use a high amount ofbattery power due to the energy demanding transcutaneous link thatcomprises an external processor with a radio transmitter configured tosend a radio frequency magnetic field into the implant in the patient'shead via a set of coils.

Since this energy demanding transmission is required to be continuouslyrunning in order to enable the hearing aid user to hear, it would bedesirable to have a less energy consuming bone conduction hearing aidthat includes an implantable prosthetic system and is configured toreceive its operating energy from an external power source using a radiofrequency link. That is, it would be advantageous to have an efficientenergy utilization mechanism, i.e. solution that allows transmission ofenergy only when there is a need for the operation of such implantedmedical devices like in an implanted transcutaneous bone conductionhearing aid.

Because, in known systems, the continued operation of the externalsignal processor during times of low energy requirement unnecessarilydrains the power source such as battery, thereby potentially depletingpower source. Therefore, there is a need to overcome the abovedisadvantage. The present disclosure provides at least an alternative tothe prior art bone conduction hearing aids.

SUMMARY

According to an aspect, a hearing device such as a bone conductionhearing aid is disclosed. The hearing device includes an implantableprosthetic system and an external audio processor device. Theimplantable prosthetic system includes a receiver coil. The externalaudio processor device may include a microphone configured to transforma received sound into an electrical input signal. The external audioprocessor device may further include a signal processor configured toprocess the electrical input signal into a processed electrical datasignal. The external audio processor device may further include atransmitter coil configured to inductively transmit data signals and/orpower, across the skin of a hearing device user, to the receiver coil ofthe implantable prosthetic system. The hearing device may furtherinclude a detection device configured to detect if the external audioprocessor device or transmitter coil is within a predefined distancefrom the implantable prosthetic system or to detect if a couplingcoefficient between the transmitter coil and a receiver coil is within apredefined value range.

The detection device may further be configured to detect if thetransmitter coil is within a predefined distance from the implantableprosthetic system or to detect if a coupling coefficient between thetransmitter coil and a receiver coil is within a predefined value range.

The transmitter coil is adapted to be external to the user body whereasthe receiver coil is adapted to be implanted within the user. Thetransmitter coil and receiver coil may be positionable behind the ear ofthe user. The transmitter coil and the receiver coil may be configuredto be operationally coupled to form a wireless transcutaneous link.

The hearing device may include a bone conduction hearing aid and inparticular, it may include a transcutaneous bone conduction hearing aid.The hearing device may include an implantable prosthetic system of anysuitable type, size and form.

Hereby, it is possible to detect if the external audio processor deviceis within a predefined distance (in close proximity to) from theimplantable prosthetic system or to detect if a coupling coefficientbetween the transmitter coil and a receiver coil is within a predefinedvalue range. Accordingly, using the hearing device according to thedisclosure it is possible to verify when transmission from thetransmitter coil is needed and when it can be turned off or turned intoa state of lower power consumption i.e. SLEEP mode (e.g. when the userremoves the processor from the head).

The hearing device may include the audio processor, power source such asa battery, transmitter coil and the detection device. The hearing devicemay further include an implantable prosthetic system (implantable part)comprising the receiver coil configured to be operationally connected toan implantable vibrator unit. The implantable prosthetic system mayinclude a processing unit that is configured to receive and process thedata and/or power received by the implantable receiver coil over thewireless transcutaneous link to generate a drive signal for theimplantable vibrator (vibrator unit). The vibrator unit is configured toprovide vibrations to the skull surface in response to the drive signal,i.e. in response to the data signal and/or power received at thereceiver coil. The vibrations are transmitted to the ear via the skullbone.

The external audio processor device may include a microphone configuredto transform a received sound into an electrical input signal. Theprocessor device may be of any suitable type. Likewise, the microphonemay be of any suitable type and form. The microphone may include one ormore multiple input microphones, e.g. for providing direction-dependentaudio signal processing. Such directional microphone system is adaptedto enhance a target acoustic source among a multitude of acousticsources in the user's environment. In one aspect, the directional systemis adapted to detect (such as adaptively detect) from which direction aparticular part of the microphone signal originates. This may beachieved by using conventionally known methods. In an embodiment, thethe microphone may be implantable.

The signal processor may be any signal processor configured to processthe electrical input signal into a processed electrical data signal. Thesignal processing unit may include amplifier that is adapted to apply afrequency dependent gain to the input audio signal. The frequencydependent gain is representative of the data that may be transmittedfrom the transmitter coil to the receiver coil.

The transmitter coil is configured to inductively transmit data signalsand/or power, across the skin of a hearing device user, to a receivercoil of the implantable prosthetic system. The transmitter coil may haveany suitable type and form.

The detection device is configured to detect if the external audioprocessor device is within a predefined distance from the implantableprosthetic system or to detect if a coupling coefficient between thetransmitter coil and a receiver coil is within a predefined value range.The detection device may comprise any suitable unit such as voltagemeasuring unit or a current measuring unit configured to detect if theexternal audio processor device is within a predefined distance from theimplantable prosthetic system.

The predefined distance may be any suitable distance e.g. less than 20mm, less than less than 15 mm, such as less than 11 mm or less than 8 mmor less than 5 mm or less than 3 mm or less than 2 mm. The predetermineddistance may be defined as a function of thickness of skin at theimplantation site such as over the mastoid region of temporal bone.

The detection device may be configured to detect if the couplingcoefficient between the transmitter coil and a receiver coil is apercentage of the maximum coupling coefficient, e.g. 80-90%, 70-80%,60-70%, 50-60%, 40-50%, 30-40% of the maximum coupling coefficient.

The detection device may further be configured to detect the distance orcoupling coefficient between the transmitter coil and the receiver coil.Hereby, it is possible to utilize the detected distance or couplingcoefficient between the transmitter coil and the receiver coil todetermine when transmission from the transmitter coil is needed and whenit can be turned off or switched to a SLEEP mode (e.g. when the userremoves the processor from the head). Accordingly, a less energyconsuming hearing device can be provided by turning off the transmittercoil when no transmission is needed.

The detection device may be configured to detect the distance betweenthe transmitter coil and the receiver coil by measuring the couplingcoefficient between the transmitter coil and the receiver coil. Thecoupling coefficient may be representatively computed by utilizing thedisclosed current measuring circuitry or voltage measuring circuitry.

The processor device may include a determination unit configured toautomatically switching operating mode of the external audio processordevice:

I) from an ON mode to a SLEEP mode/OFF mode or

II) from a SLEEP mode/OFF mode to an ON mode in accordance with thedetermined distance or determined coupling coefficient.

Hereby, the determination unit of the processor device is capable ofsaving energy by automatically switching operating mode of the externalaudio processor device from an ON mode to a SLEEP mode/OFF mode when thedetermined distance or determined coupling coefficient indicates thatthe transmitter coil does not need to be active i.e. in deactivatedstate (e.g. when the user takes off the external audio processor).Moreover, the determination unit of the processor device is capable ofautomatically switching operating mode of the external audio processordevice from a SLEEP mode/OFF mode to an ON mode in accordance with thedetermined distance or determined coupling coefficient. Accordingly, thedetermination unit of the processor device can activate (i.e. activatedstate) the transmitter coil when needed (e.g. when the user puts on theexternal audio processor).

The hearing device may be configured to be in SLEEP mode/OFF mode or tobe switched into SLEEP mode/OFF mode. The SLEEP mode/OFF mode is anenergy saving mode in which the transmitter coil is deactivate, i.e. nottransmitting data and/or power. Hereby, electrically power can be saved.Although the transmitter is deactivated in both the SLEEP and OFF mode,but in the OFF mode all electrical components are in switched off modewhereas in the SLEEP mode, other electrical components are in low powermode.

The hearing device may be configured to be in ON mode or to be switchedinto ON mode. The ON mode is a mode in which the transmitter coil isactivate, i.e. transmitting data and/or power.

The detection device may further include a parameter measuringcircuitry, which in response to a controlled signal of predefinedcharacteristics applied to the transmitter coil is configured to measurea quantity value associated with the transmitter coil and/or processordevice for determining the distance or coupling coefficient between thetransmitter coil and the receiver coil. Hereby, the parameter measuringcircuitry allows for applying a controlled signal of predefinedcharacteristics to the transmitter coil in order to measure a quantityvalue associated with the transmitter coil and/or processor device fordetermining the distance or coupling coefficient between the transmittercoil and the receiver coil.

Accordingly, it is possible to apply a suitable controlled signal ofpredefined characteristics to the transmitter coil for the purpose ofdetermining the distance or coupling coefficient between the transmittercoil and the receiver coil in an easy and/or effective manner.

The controlled signal may be provided using a battery, which is housed,may be in a battery compartment, within a processor housing. Hereby, thedistance or coupling coefficient between the transmitter coil and thereceiver coil can be determined in by using technical features alreadyavailable in standard hearings aids.

The parameter measuring circuitry may include a current measuringcircuitry, wherein the controlled signal comprises a current signal,wherein the predefined characteristics comprises a current of predefinedmagnitude corresponding to a stimulation current level for a specificfrequency for the user, and the measured quantity value is thetransmitter coil current and/or the processor device current.

The current measuring circuitry of the parameter measuring circuitry maybe used to measure if the magnitude of a measured current signal throughthe transmitter coil corresponds to a stimulation current level for aspecific frequency for the user. Accordingly, the hearing device candetermine the distance or coupling coefficient between the transmittercoil and the receiver coil in an easy and reliable manner.

The parameter measuring circuitry may include a voltage measuringcircuitry, wherein the controlled signal comprises a voltage, whereinthe predefined characteristics comprises a voltage generating a currentof predefined magnitude corresponding to a stimulation current level fora specific frequency for the user, and the measured quantity value isthe voltage across the transmitter coil and/or voltage across theprocessor device.

In this scenario, the voltage measuring circuitry of the parametermeasuring circuitry can be used to measure if the magnitude of ameasured voltage signal across the transmitter coil corresponds to astimulation current level for a specific frequency for the user for aspecific frequency for the user. Accordingly, the hearing device candetermine the distance or coupling coefficient between the transmittercoil and the receiver coil in an easy and reliable manner.

The detection device may be configured to access a characteristicquantity value stored in a memory, which is housed within the processorhousing and the characteristic quantity value being defined inaccordance with a frequency curve parameters defining force output ofthe vibrator as a function of frequency.

Hereby, the detection device is capable of storing and accessing thecharacteristic quantity value. Accordingly, the characteristic quantityvalue can be used for a subsequent process such as comparison with ameasured quantity value in order to determine the distance or couplingcoefficient between the transmitter coil and the receiver coil in aneasy and reliable manner.

The detection device may be configured to compare the measured quantityvalue with the accessed characteristic quantity value. Hereby, thedetection device can determine the distance or coupling coefficientbetween the transmitter coil and the receiver coil by comparing themeasured quantity value with the accessed characteristic quantity value.

The detection device may be configured to generate a compared resultbased on the comparison, representing the determined distance orcoupling coefficient between the transmitter coil and a receiver coil.

Hereby, the detection device can be used to determine if the transmittercoil needs to be deactivated (e.g. when the user takes off the hearingdevice) or needs to be activated (e.g. when the user puts on the hearingdevice).

The detection device may be configured to instruct the determinationunit to, with the transmitter coil and/or external audio processor inthe SLEEP/OFF mode, automatically switch the transmitter coil and/orexternal audio processor from the SLEEP/OFF mode to ON mode if thecompared result is within a predefined acceptable variation.

Hereby, the hearing device can automatically be switched from theSLEEP/OFF mode to the ON mode by defining a suitable predefinedacceptable variation range. Moreover, the device can be maintained inthe SLEEP/OFF mode as long as the compared result is not within(outside) the predefined acceptable variation.

The detection device may be configured to instruct the determinationunit to, with the transmitter coil and/or external audio processor inthe SLEEP/OFF mode, automatically maintain the transmitter coil and/orexternal audio processor in the SLEEP/OFF mode if the compared result isoutside the predefined acceptable variation.

Hereby, the hearing device can be maintained in the SLEEP/OFF mode aslong as the compared result is outside the predefined acceptablevariation.

The detection device may be configured to instruct the determinationunit to, with the transmitter coil and/or external audio processor inthe ON mode, automatically switch the transmitter coil and/or externalaudio processor from the ON mode to SLEEP/OFF mode if the comparedresult is outside a predefined acceptable variation.

Accordingly, the hearing device may automatically be switched into anenergy saving mode when the transmitter coil is not required to beactively transmitting. Therefore, the determination unit is adapted toprevent transmission. Accordingly, a less energy consuming hearingdevice can be provided.

The detection device may be configured to instruct the determinationunit to, with transmitter coil and/or external audio processor in the ONmode, maintain the transmitter coil and/or external audio processor inthe ON mode if the compared result is within a predefined acceptablevariation (range).

Hereby, the device can be maintained in the ON mode as long as thecompared result is within the predefined acceptable variation (range).

The predefined acceptable variation may correspond to the predefineddistance or the predefined value range.

Hereby, the acceptable variation (range) can be used to determine if thepredefined distance or coupling coefficient between the transmitter coiland the receiver coil is within the predefined distance range or thepredefined value range.

Accordingly, the acceptable variation (range) can be used as a referencefor determining if the with transmitter coil and/or external audioprocessor should be maintained in its mode or be switched into anothermode.

During the SLEEP/OFF mode, the determination unit may be configured todeactivate transmission from the transmitter coil for a first predefinedtime period. Hereby, it is possible to deactivate the transmitter coilin order to reduce the power consumption in a predefined time period. Itmay be an advantage that the determination unit is configured toactivate transmission from the transmitter coil automatically when thefirst time period has expired.

During the SLEEP/OFF mode, the determination unit may be configured todeactivate transmission from the transmitter coil for a first predefinedtime period, wherein the determination unit is configured to activatethe transmitter coil for a second predefined time period, during whichthe measured quantity value and comparison result are generated fordetermining if the external audio processor device is within apredefined distance from the implantable prosthetic system or if acoupling coefficient between the transmitter coil and a receiver coil iswithin a predefined value range, wherein:

-   -   if the compared result is within the predefined acceptable        variation, then the determination unit is configured to        automatically switch the transmitter coil from the SLEEP/OFF        mode to ON mode or    -   if the compared result is outside the predefined acceptable        variation, then the determination unit is configured to        deactivate and switch back the transmitter coil to the SLEEP/OFF        mode.

Hereby, it is possible to:

-   -   automatically switch the transmitter coil from the SLEEP/OFF        mode to ON if the compared result is within the predefined        acceptable variation;    -   automatically deactivate and switch back the transmitter coil to        the SLEEP/OFF mode, if the compared result is outside the        predefined acceptable variation.

Accordingly, the hearing device is configured to save power and stillensure that the transmitter coil is activated when needed.

During the ON mode, the determination unit may be configured to duringrecurrent time periods, generating the measured quantity value andcomparison result for determining if the external audio processor deviceis within a predefined distance from the implantable prosthetic systemor if a coupling coefficient between the transmitter coil and a receivercoil is within a predefined value range; wherein if the compared resultis within the predefined acceptable variation, then the determinationunit is configured to maintain the transmitter coil in the ON mode; orif the compared result is outside the predefined acceptable variation,then the determination unit is configured to deactivate andautomatically switch the transmitter coil from ON mode to the SLEEP/OFFmode.

Hereby, it is possible to provide a hearing device that is configured tosave power and still ensure that the transmitter coil is activated whenneeded.

In some situations, such as when the transmitter coil is proximate to ametal plate instead of the receiver coil, the measured current may bewithin the normal usage range. Therefore, in order to avoid a falsepositive and automatic switching to ON mode, refinement to the Auto-Onmay be applied.

The implanted part of the implantable bone conduction hearing aidincludes an electromagnetic vibrator, which has known characteristicimpedance that varies across the audio frequency range, and a mechanicalresonance typically within a 700 Hz-1000 Hz. Such electromagneticvibrators are known in the art such as in U.S. Pat. Nos. 8,798,300,6,751,334, which are incorporated herein by reference. Thus across afrequency range, in position of use (coupled transmitter and receivercoil), the characteristic impedance of the vibrator affects the measuredtransmitter current/voltage across the transmitter coil in a predictableway when a controlled signal of predefined characteristics is applied tothe transmitter coil.

Therefore, in an embodiment, when a current measurement or voltagemeasurement within the normal range is detected, further transmittercurrent measurements or transmitter voltage measurement at differentfrequencies may be performed and compared with transmitter current orvoltage corresponding to the different frequencies for the transmitterpositioned on the head situation. This may be performed by transmittingone or more discrete tones at high frequency modulation or via afrequency sweep.

When the compared result based on the measured quantity value is withinthe predefined acceptable variation, the parameter measuring circuitrymay be configured to measure at least one subsequent quantity valueassociated with the transmitter coil and/or processor device in responseto at least one subsequent controlled signal of at least one subsequentpredefined characteristics applied to the transmitter coil.

Hereby, for a vibrator with known characteristic frequency curve, itwould be possible to compare the pattern of measured current and thecurrent from the known characteristic curve to determine whether theexternal audio processor device is close to the implantable prostheticdevice or another object. Accordingly, if the condition is satisfied,the external audio processor device returns to normal mode of theoperation, else the external audio processor device stays in OFFmode/Sleep mode.

The external audio processor device may be configured to continuallygoes through a cyclical step of determining whether the implant isnearby.

The detection device may be configured to access at least onecharacteristic quantity value stored in the memory, which is housedwithin the processor housing and the at least one characteristicquantity value being defined in accordance with the frequency curveparameters of the hearing device; and generate at least one comparedresult by comparing the at least one subsequent measure quantity valuewith corresponding the at least one accessed characteristic quantityvalue.

Hereby, the hearing device is capable of applying characteristicquantity value stored in the memory.

The determination unit may be configured to automatically switch thetransmitter coil and/or external audio processor from the SLEEP/OFF modeto ON mode if the compared result and at least one additional comparedresult is within the predefined acceptable variation and at leastsubsequent predefined acceptable variation respectively.

Hereby, it is ensured that hearing device is switched in to the ON modewhen required.

The controlled signal and the at least one subsequent controlled signalmay include one or more discrete tones at a predefined modulation or afrequency sweep. Hereby, it is possible to let the determination unitapply a predefined reliable and valid methodology comprising acontrolled signal and the at least one subsequent controlled signal.

The processor device may include a processor housing provided with abattery arranged in a battery compartment within the processor housing.

No transmission over the wireless transcutaneous link may beaccomplished by the transmitter coil during at least a portion of thepower saving mode.

The determination unit may be configured to automatically switching thehearing device and hereby the external audio processor device from an ONmode to an OFF mode/Sleep mode. Hereby, electrical power can be saved.

The processor device may include a determination unit configured toautomatically switching the hearing device and hereby the external audioprocessor device from the power saving mode to the ON mode. Hereby, itis ensured that the hearing device can be brought into ON mode whenrequired.

The processor device may include a coupling determination unitconfigured to determine the coupling coefficient between the transmittercoil and the receiver coil. Hereby, it is possible to apply the couplingcoefficient between the transmitter coil and the receiver coil todetermine if the hearing device should be switched from one mode intoanother mode or if the hearing device should be maintained in the samemode.

The current measuring circuitry or voltage measuring circuitry may beconfigured to measure a mean value of the current or voltage for apredefined time period. Hereby, the mean value of the current or voltagecan be used to determine if the hearing device should be switched fromone mode into another mode or if the hearing device should be maintainedin the same mode.

The current measuring circuitry or voltage measuring circuitry may beconfigured to measure a mean value of the current or voltage for apredefined time period of at least 10 mS, such as 100 mS or 1 second.

The hearing device may include a user interface member (e.g. apushbutton or a touch screen or gesture controls) for manually switchingthe hearing device to the ON mode and/or an OFF mode. Hereby, it ispossible to manually control the hearing device.

The processor device may be configured to deactivate transmission fromthe transmitter coil for a first predefined time period and activate thetransmitter coil for a second predefined time period during an OFFmode/Sleep Mode (power saving mode), wherein the detection device isconfigured to detect if the external audio processor device is within apredefined distance from the implantable prosthetic system during thetime periods in which the transmitter coil is activated. Hereby, it ispossible to deactivate the hearing device and on a regular basisdetermine if the hearing device should be turned on.

The processor device may be configured to switch the hearing device andhereby the external audio processor device to an ON mode when theexternal audio processor device is within a predefined distance from theimplantable prosthetic system. Hereby, it is ensured that the hearingdevice is activated when required.

The predefined distance may correspond to the distance between theexternal audio processor device and the implantable prosthetic systemduring normal operation.

The first predefined time period (T₁) may be about 0-1 seconds, such as0.5 seconds and where the second predefined time period (T₂) is about2-10 seconds, such as 3-5 seconds, such as about 3.5 seconds.

The hearing device may include a current measuring circuitry configuredto measure additional transmitter coil currents and/or processor devicecurrents when a current measurement is detected falling within apredefined normal range, wherein the additional transmitter coilcurrents and/or processor device currents are measured by transmittingone or more discrete tones at a predefined frequency modulation or via afrequency sweep.

The processor device may be configured to detect if the measuredadditional transmitter coil currents and/or processor device currentsmatches a predefined range of the transmitter current with the hearingdevice in operational position.

The hearing device may be configured to returns to ON mode if themeasured additional transmitter coil currents and/or processor devicecurrents matches the predefined range of the transmitter current withthe hearing device in operational position and otherwise stay in OFFmode/Sleep mode (power saving mode).

According to another aspect of the disclosure, the hearing systemcomprising a hearing device according to the disclosure and animplantable prosthetic system comprising a transducer for generating anoutput signal.

The transducer may be an implanted vibrator configured to generatemechanical vibrations.

The transducer is a stimulator secured in bone beneath the skin, whereinthe stimulator is configured to convert the received signals intoelectric impulses and send them through an internal cable to an array ofelectrodes wound through the cochlea. An illustrative implementation isshown in US patent US7670278, which is incorporated herein by reference.

BRIEF DESCRIPTION OF DRAWINGS

The aspects of the disclosure may be best understood from the followingdetailed description taken in conjunction with the accompanying figures.The figures are schematic and simplified for clarity, and they just showdetails to improve the understanding of the claims, while other detailsare left out. Throughout, the same reference numerals are used foridentical or corresponding parts. The individual features of each aspectmay each be combined with any or all features of the other aspects.These and other aspects, features and/or technical effect will beapparent from and elucidated with reference to the illustrationsdescribed hereinafter in which:

FIG. 1A shows a cross-sectional view of a hearing device arranged on ahearing device user;

FIG. 1B shows a close-up view of the hearing device shown in FIG. 1A;

FIG. 2A shows a first graph with two alternating phases;

FIG. 2B shows a second graph with two alternating phases;

FIG. 2C shows a third graph with two alternating phases;

FIG. 2D shows a vibrator characteristic curve of a hearing device;

FIG. 3A shows a hearing device arranged on a hearing device user;

FIG. 3B shows the hearing device shown in FIG. 5A provided in a distancefrom the head of the hearing device user; and

FIG. 4 shows an illustration of the bone conduction hearing device.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations. Thedetailed description includes specific details for the purpose ofproviding a thorough understanding of various concepts. However, it willbe apparent to those skilled in the art that these concepts may bepractised without these specific details. Several aspects of theapparatus and methods are described by various blocks, functional units,modules, components, circuits, steps, processes, algorithms, etc.(collectively referred to as “elements”). Depending upon particularapplication, design constraints or other reasons, these elements may beimplemented using electronic hardware, computer program, or anycombination thereof.

The electronic hardware may include microprocessors, microcontrollers,digital signal processors (DSPs), field programmable gate arrays(FPGAs), programmable logic devices (PLDs), gated logic, discretehardware circuits, and other suitable hardware configured to perform thevarious functionality described throughout this disclosure. Computerprogram shall be construed broadly to mean instructions, instructionsets, code, code segments, program code, programs, subprograms, softwaremodules, applications, software applications, software packages,routines, subroutines, objects, executables, threads of execution,procedures, functions, etc., whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.

A hearing device may include a hearing aid that is adapted to improve oraugment the hearing capability of a user by receiving an acoustic signalfrom a user's surroundings, generating a corresponding audio signal,possibly modifying the audio signal and providing the possibly modifiedaudio signal as an audible signal to at least one of the user's ears.The “hearing device” may further refer to a device adapted to receive anaudio signal electronically, possibly modifying the audio signal andproviding the possibly modified audio signals as an audible signal to atleast one of the user's ears. Such audible signals may be provided inthe form of an acoustic signal transferred as mechanical vibrations tothe user's inner ears through bone structure of the user's head and/orthrough parts of middle ear of the user or electric signals transferreddirectly or indirectly to cochlear nerve and/or to auditory cortex ofthe user.

The hearing device is adapted to be worn in any known way. This mayinclude i) arranging an external unit of the hearing device behind theear and positioning it over an implanted unit through magneticattraction between the external unit and the implanted unit such as in atranscutaneous bone conduction hearing aid.

A “hearing system” refers to a system comprising one or two hearingdevices, and a “binaural hearing system” refers to a system comprisingtwo hearing devices where the devices are adapted to cooperativelyprovide audible signals to both of the user's ears. The hearing systemor binaural hearing system may further include auxiliary device(s) thatcommunicates with at least one hearing device, the auxiliary deviceaffecting the operation of the hearing devices and/or benefitting fromthe functioning of the hearing devices. A wired or wirelesscommunication link between the at least one hearing device and theauxiliary device is established that allows for exchanging information(e.g. control and status signals, possibly audio signals) between the atleast one hearing device and the auxiliary device. Such auxiliarydevices may include at least one of remote controls, remote microphones,audio gateway devices, mobile phones, public-address systems, car audiosystems or music players or a combination thereof. The audio gateway isadapted to receive a multitude of audio signals such as from anentertainment device like a TV or a music player, a telephone apparatuslike a mobile telephone or a computer, a PC. The audio gateway isfurther adapted to select and/or combine an appropriate one of thereceived audio signals (or combination of signals) for transmission tothe at least one hearing device. The remote control is adapted tocontrol functionality and operation of the at least one hearing devices.The function of the remote control may be implemented in a SmartPhone orother electronic device, the SmartPhone/electronic device possiblyrunning an application that controls functionality of the at least onehearing device.

In general, a hearing device includes i) an external input unit such asa microphone for receiving an acoustic signal from a user's surroundingsand providing a corresponding electrical input signal, ii) an externalsignal processor adapted to process the electrical input signal, iii) atransmitter coil adapted to transmit the processed electrical inputsignal, iv) an implanted receiver coil adapted to receive the processedelectrical input signal and power from the transmitter coil, and v) astimulator unit adapted to receive the processed electrical input signalfrom the receiver coil and to produce stimulation that is perceived assound by the hearing aid user.

The input unit may include multiple input microphones, e.g. forproviding direction-dependent audio signal processing. Such directionalmicrophone system is adapted to enhance a target acoustic source among amultitude of acoustic sources in the user's environment. In one aspect,the directional system is adapted to detect (such as adaptively detect)from which direction a particular part of the microphone signaloriginates. This may be achieved by using conventionally known methods.The signal processing unit may include amplifier that is adapted toapply a frequency dependent gain to the input audio signal. The signalprocessing unit may further be adapted to provide other relevantfunctionality such as compression, noise reduction, etc. The stimulatorunit may include an output transducer such as a vibrator that convertsproduces mechanical vibrations such as in bone conduction hearing aid orone or more output electrodes for providing the electric signals such asin a Cochlear Implant.

Now referring to FIG. 1A, which illustrates a hearing device 2 accordingto an aspect of the disclosure shows a cross-sectional view of a hearingdevice 2 such as a transcutaneous bone conduction hearing aid arrangedon a hearing aid user 8.

The hearing device 2 (surrounded by a dotted line) is a transcutaneousbone anchored hearing device 2 comprising an external audio processordevice 4 connected to a coupling member 6. The coupling member 6 of thehearing device 2 is attached to the skin 10 of the hearing device user 8behind the ear 18 of the hearing device user 8 by means of magneticattraction between an external magnet (not shown) and an implantablemagnet (not shown) of an implantable prosthetic device 16 implantedsubcutaneously under the skin 10 into the skull bone 14. The implantableprosthetic device 16 is a small implant (typically made of titanium)that is mounted on the skull bone 14 behind the ear 18. The implantableprosthetic device 16 comprises an implantable magnet (not shown)attached and hidden beneath the skin 10. The external audio processordevice 4 of the hearing device 2 is attached to an external magnet (notshown) and the external audio processor device 4 is kept in place bymagnetic attraction between the implant magnet and the external magnet(not shown). Sound 34 received by the external audio processor device 4is processed and along with power is transmitted from the external audioprocessor device 4 using an external transmitted coil to an implantablereceiver coil of the implantable prosthetic device 16. The signal(representative of sound processed by the external audio processordevice 16) received at the receiver coil is delivered to an implantedvibrator that produces mechanical vibrations, which are directed throughthe skull bone 14 to the inner ear for producing sound perception.

FIG. 1B illustrates a close-up view of the hearing device 2 shown inFIG. 1A. It can be seen that the hearing device 2 comprises an externalaudio processor device 4 having a microphone 36 provided in a housing38. The external audio processor device 4, moreover, comprises a battery42 arranged in a battery compartment 44. The external audio processordevice 4, additionally, comprises a signal processor 28,

The hearing device 2 comprises a coupling member 6 provided with a skincontact surface 26 configured to be brought into contact with the skin10 of the hearing device user 8 when the hearing device 2 is attached onthe hearing device user 8. The coupling member 6 may include a detectiondevice 30 arranged below a transmitter coil 22. The detection device 30may be arranged within the housing 38.

An implantable prosthetic device 16 is provided next to the hearingdevice 2. The implantable prosthetic device 16 comprises a receiver coil24 and a vibrator 32. The vibrator 32 is adapted to be positioned on theouter skull surface or in recess created in the skull bone.

Sound 34 is received by the microphone 36 of the external audioprocessor device 4. The sound 34 received by the microphone 36 isprocessed by the signal processor 28 and transmitted to the receivercoil 24 as a signal 20 by the transmitter coil 22. The vibrator 32 ofthe implantable prosthetic device 16 is configured to generatevibrations that are directed through the skull bone 14 to stimulate theinner ear.

FIG. 2A illustrates a curve showing the activity of the external audioprocessor device of a hearing device according to an aspect of thedisclosure. The activity is plotted against time in on the X-axis andstate (ON or OFF/SLEEP) on the Y-axis. T₁ represents transmitter in anactivated state and T₂ represents transmitter in a deactived state. Theexternal audio processor device is in ON mode (first T1 time period) andonce it is determined based on the quantity measurement that thetransmitter should be in OFF/SLEEP mode, then following the ON mode, thetransmitter is switched to OFF/SLEEP mode for time periods T₂. Duringthe OFF/SLEEP mode, the transmitter may be temporarily switched on (asindicated by following T1 time periods), interrupting the OFF/SLEEPperiod, for measuring the quantity. During the temporarily ON mode, thequantity (e.g. current) of the transmitter coil is measured and comparedagainst the normal (expected) range. If the measured current is outside,i.e. outside, the normal (expected) range, the external audio processordevice is switched back from temporarily ON mode to the power saving OFFmode/sleep mode ((as indicated by follow up T₂ period). Alternatively,if the measured current is within the normal (expected) range, theexternal audio processor device remains in the ON mode (or is switchedto permanent ON mode).

FIG. 2B illustrates a second curve showing the activity of the externalaudio processor device of a hearing device according to an aspect of thedisclosure. The curve basically corresponds to the one shown in FIG. 2Aexcept that the initial state of the hearing device is shown as anOFF/SLEEP mode. Also, the OFF mode/sleep mode time periods T₂, however,are significantly shorter than the ones shown in FIG. 2A. Thetemporarily ON mode time periods T₁ are also significantly shorter thanthe one shown in FIG. 2A.

FIG. 2C illustrates a third curve showing the activity of the externalaudio processor device of a hearing device according to an aspect of thedisclosure. The curve basically corresponds to the one shown in FIG. 2B,however, the OFF mode/sleep mode time periods T₂ are shorter than theones shown in FIG. 3A and longer than the ones shown in FIG. 2B. Thetemporarily ON mode time periods T₁ are shorter than the one shown inFIG. 2A and longer than the ones shown in FIG. 2B.

As seen in FIG. 2A, FIG. 2B and FIG. 2C, it is possible to select theOFF mode/sleep mode time periods T₂ and the temporarily ON mode timeperiods T₁ as desired.

FIG. 2D illustrates a vibrator characteristic curve of a hearing devicesuch as a bone conduction hearing aid. The signal force generated by avibrator (generally electromagnetic) of a bone conduction hearing aidrelates to alternating current (and voltage) applied to the coil of thevibrator. This alternating current (voltage) applied to the coil of thevibrator corresponds to the transmitter coil current/voltage across thetransmitter coil, producing magnetic flux lines received by the receivercoil and eventually as alternating current by the coil of the vibrator.

The vibrator frequency curve shown in FIG. 2D, shows the force output ofan implantable vibrator as a function of frequency. This frequency curveof the implantable vibrator, showing the force output as a function offrequency, represents frequency specific applied current to the vibratorcoil and this in turn relates to characteristic transmitter coil current(or characteristic voltage across the transmitter coil). Thecharacteristic transmitter coil current or characteristic voltage acrossthe transmitter coil represent the characteristic parameter value. Thus,using a current measuring circuit (or alternatively a voltage measuringcircuit) enables comparison of frequency specific transmitter currentvalue (or alternatively voltage) across the transmitter coil during ONmode or OFF/SLEEP mode and the frequency specific characteristic current(or alternatively voltage).

In FIG. 2D a first frequency F₁ and a second frequency F₂ (that mayrepresent one or more discrete tones) are indicated. Two vibrationlevels Y₁, Y₂ corresponding to the characteristic current (oralternatively voltage) at the first frequency F₁ and the secondfrequency F₂, respectively. The vibration levels Y1 and Y2 correspond toa specific characteristic transmitter current (or characteristic voltagevalue across the transmitter coil). Therefore, in one embodiment,performing the more than one discrete measurements and making acomparison with characteristic transmitter coil current value (orcharacteristic voltage value across the transmitter coil) for eachfrequency would allow to ascertain whether the measure quantity value(current or voltage) is an expected value (range) and accordingly thehearing device may be switched between different modes (ON orOFF/SLEEP). Thus, false positive for mode change may be avoided. Inanother embodiment, only one measurement and comparison is enough todetermine whether the mode needs to be changed or not.

In the situation illustrated in FIG. 3A the distance D₁ between thecoupling member 6 and the implantable prosthetic device 16 is as shortas it can be since the external audio processor device 4 is attached tothe skin 10 next to the ear 18 of the hearing device user 8.

FIG. 3B, however, shows the hearing device 2 shown in FIG. 3A providedin a distance from the head of the hearing device user 8. The distanceD₂ between the coupling member 6 and the implantable prosthetic device16 is larger than the distance D₁ in FIG. 5A.

The hearing device 2 is equipped with a detection device (not shown)configured to determine if the external audio processor device 4 iswithin a predefined distance from the implantable prosthetic system 16or to determine if a coupling coefficient between the transmitter coil(not shown) of the coupling member 6 and a receiver coil (not shown) ofthe implantable prosthetic system 16 is within a predefined value range.

Accordingly, if the distance D₂ exceeds a certain value the hearingdevice 2 automatically detects that the distance D₂ exceeds this valueand switches the hearing device 2 from the ON mode to the SLEEP mode/OFFmode, if the hearing device 2 is in the ON mode. On the other hand, ifthe hearing device 2 already is in the SLEEP mode/OFF mode, it will beremained in the SLEEP mode/OFF mode.

If the hearing device is in the SLEEP mode/OFF mode and the distance D₂does not exceeds this value, the hearing device 2 automatically detectsthat the distance D₂ does not exceeds this value and switches thehearing device 2 from the SLEEP mode/OFF mode to the ON mode.

FIG. 4 shows an illustration of the bone conduction hearing device 400.The device 400 is adapted for processing signals comprising audio inorder to assist a hearing impaired user. The hearing aid device 10comprises a first microphone 404, and preferably additional microphonessuch as a second microphone 404′. The microphones are adapted to capturesound 402 from the surrounding and to covert it into an electricalsignal.

The hearing device further includes an electrical circuitry 406 thatcomprises different functional units for example processing unit 412,analog-to-digital converter 410, memory 418, detection unit 416 anddetermination unit 420. The electrical signal comprising audio 402 areusually provided to an analog-digital-converter 410, which digitizes thesignal to generate a digitized signal. The digitized signal is providedto the signal processing unit 412. The signal processing unit 412 isadapted to process the digitized signals to generate a processed signalin accordance with the needs of the hearing impaired user 48. The signalprocessing unit may include a filter bank in order to filter theincoming digitized signal in different frequency bands and process thebands by applying frequency specific amplification or other processingalgorithms, which may include noise reduction, spatial directionalityselection, sound source localization, gain reduction/enhancement,frequency filtering, and/or other processing operations common forhearing aids. The processed signal is transmitter using a transmitter414 and an inductive link 426 across the skin 436 of the user. The powersupply 408 provides energy for the operation of the external part andthe implantable part of the hearing aid device. The signal processor 412is adapted to modulate the processed signal in such a way that both datacontaining audio information and power may be transmittedtranscutaneously across the skin.

The implantable part 428 comprises a receiver unit 430 that is adaptedto receive the transmitted processed signal. The received signal isdemodulated in a data signal and power signal at a demodulator 432. Thepower signal is used to supply energy to the implanted componentsincluding a vibrator 434, which utilizes the data signal to producefrequency specific vibrations to a bone such as a skull bone. Thevibrations are transmitted via the skull bone to cochlea, thusgenerating sound perception to the hearing aid user.

The external part of the hearing aid device further comprises adetection unit 416, which may include at least one of the currentmeasuring circuit 422 and voltage measuring circuit 424. Furthermore,the hearing aid includes a determination unit 420 and may also include amemory 418. The functioning of these components are in accordance withthe description provided earlier in different combinable embodiments ofthis application.

It is intended that the structural features of the devices describedabove, either in the detailed description and/or in the claims, may becombined with steps of the method, when appropriately substituted by acorresponding process.

It should be appreciated that reference throughout this specification to“one embodiment” or “an embodiment” or “an aspect” or features includedas “may” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the disclosure. Furthermore, the particular features,structures or characteristics may be combined as suitable in one or moreembodiments of the disclosure. The previous description is provided toenable any person skilled in the art to practice the various aspectsdescribed herein. Various modifications to these aspects will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other aspects.

The claims are are to be accorded the full scope consistent with thelanguage of the claims, wherein reference to an element in the singularis not intended to mean “one and only one” unless specifically sostated, but rather “one or more.” Unless specifically stated otherwise,the term “some” refers to one or more.

Accordingly, the scope should be judged in terms of the claims thatfollow.

1. A hearing device comprising: an implantable prosthetic systemincluding a receiver coil and a vibrator; a memory; and an externalaudio processor device comprising a microphone configured to transform areceived sound into an electrical input signal, a signal processorconfigured to process the electrical input signal into a processedelectrical data signal, a transmitter coil configured to inductivelytransmit data signals and/or power across a user's skin to the receivercoil, and a detection device configured to detect if the external audioprocessor device is within a predefined distance from the implantableprosthetic system or to detect if a coupling coefficient between thetransmitter coil and the receiver coil is within a predefined valuerange, wherein the external audio processor device further comprises: adetermination unit configured to automatically switch operating modes ofthe transmitter coil and/or the external audio processor device I) froman ON mode to a SLEEP/OFF mode, or II) from a SLEEP/OFF mode to an ONmode in accordance with the determined distance or the determinedcoupling coefficient, and wherein during SLEEP/OFF mode, thedetermination unit is configured to deactivate transmission from thetransmitter coil for a first predefined time period, activate thetransmitter coil for a second predefined time period following the firstpredefined time period, during which the measured quantity value andcompared result are generated for determining if the external audioprocessor device is within a predefined distance from the implantableprosthetic system or if a coupling coefficient between the transmittercoil and a receiver coil is within a predefined value range; and whereinif the compared result is within the predefined acceptable variation,then the determination unit is configured to automatically switch thetransmitter coil and/or external audio processor device from SLEEP/OFFmode to ON mode, or if the compared result is outside the predefinedacceptable variation, then the determination unit is configured todeactivate the transmitter coil and switch the transmitter coil and/orexternal audio processor device back to SLEEP/OFF mode.
 2. The hearingdevice according to claim 1, wherein the detection device is configuredto detect whether the external audio processor device is within thepredefined distance from the implantable prosthetic system using thegenerated compared result.
 3. The hearing device according to claim 1,wherein the controlled signal is provided using a battery, which ishoused in a housing of the external audio processor device.
 4. A hearingdevice according to claim 1, wherein I) the parameter measuringcircuitry comprises current measuring circuitry, the controlled signalincludes a current signal, the predefined characteristics include acurrent of predefined magnitude corresponding to a stimulation currentlevel for a specific frequency for the user, and the measured quantityvalue is the transmitter coil current and/or the external audioprocessor device current; or II) the parameter measuring circuitrycomprises voltage measuring circuitry, the controlled signal includes avoltage, the predefined characteristics include a voltage generating acurrent of predefined magnitude corresponding to a stimulation currentlevel for a specific frequency for the user, and the measured quantityvalue is a voltage across the transmitter coil and/or a voltage acrossthe external audio processor device.
 5. The hearing device according toclaim 1, wherein the detection device is further configured to instructthe determination unit to I) with the transmitter coil and/or externalaudio processor in SLEEP/OFF mode, automatically switch the transmittercoil and/or external audio processor from SLEEP/OFF mode to ON mode ifthe compared result is within a predefined acceptable variation, or II)with the transmitter coil and/or external audio processor in SLEEP/OFFmode, maintain the transmitter coil and/or external audio processor inSLEEP/OFF mode if the compared result is outside the predefinedacceptable variation; or III) with the transmitter coil and/or externalaudio processor in ON mode, automatically switch the transmitter coiland/or external audio processor from ON mode to SLEEP/OFF mode if thecompared result is outside a predefined acceptable variation, or IV)with the transmitter coil and/or external audio processor in ON mode,maintain the transmitter coil and/or external audio processor in ON modeif the compared result is within a predefined acceptable variation. 6.The hearing device according to claim 5, wherein the predefinedacceptable variation corresponds to the predefined distance or thepredefined value range.
 7. The hearing device according to claim 1,wherein during the ON mode, the determination unit is configured togenerate, during recurrent time periods, the measured quantity value andcompared result for determining if the external audio processor deviceis within the predefined distance from the implantable prosthetic systemor if the coupling coefficient between the transmitter coil and thereceiver coil is within the predefined value range; and if the comparedresult is within the predefined acceptable variation, then thedetermination unit is configured to maintain the transmitter coil and/orthe external audio processor device in the ON mode, or if the comparedresult is outside the predefined acceptable variation, then thedetermination unit is configured to deactivate the transmitter coil andautomatically switch the transmitter coil and/or the external audioprocessor device from ON mode to the SLEEP/OFF mode.
 8. The hearingdevice according to claim 1, wherein when the compared result based onthe measured quantity value is within the predefined acceptablevariation, the parameter measuring circuitry is configured to measure atleast one subsequent quantity value associated with the transmitter coiland/or external audio processor device in response to at least onesubsequent controlled signal of at least one subsequent predefinedcharacteristics applied to the transmitter coil.
 9. The hearing deviceaccording to claim 8, wherein the detection device is further configuredto access at least one subsequent characteristic quantity value storedin the memory, the at least one subsequent characteristic quantity valuebeing defined in accordance with the frequency curve parameters of thehearing device; and generate at least one subsequent compared result bycomparing the at least one subsequent measured quantity value with theat least one accessed subsequent characteristic quantity value.
 10. Thehearing device according to claim 9, wherein the determination unit isfurther configured to automatically switch the transmitter coil and/orexternal audio processor from SLEEP/OFF mode to ON mode if the comparedresult and at least one subsequent compared result is within thepredefined acceptable variation and at least subsequent predefinedacceptable variation respectively.
 11. The hearing device according toclaim 1, wherein the controlled signal and the at least one subsequentcontrolled signal comprise one or more discrete tones at a predefinedmodulation or a frequency sweep.
 12. The hearing device according toclaim 2, wherein the external audio processor device further comprises adetermination unit configured to automatically switch operating modes ofthe external audio processor device and/or transmitting coil I) from anON mode to a SLEEP/OFF mode, or II) from SLEEP/OFF mode to ON mode inaccordance with the determined distance or determined couplingcoefficient.
 13. A hearing device according to claim 2, wherein I) theparameter measuring circuitry comprises current measuring circuitry, thecontrolled signal includes a current signal, the predefinedcharacteristics include a current of predefined magnitude correspondingto a stimulation current level for a specific frequency for the user,and the measured quantity value is the transmitter coil current and/orthe external audio processor device current; or II) the parametermeasuring circuitry comprises voltage measuring circuitry, thecontrolled signal includes a voltage, the predefined characteristicsinclude a voltage generating a current of predefined magnitudecorresponding to a stimulation current level for a specific frequencyfor the user, and the measured quantity value is the voltage across thetransmitter coil and/or voltage across the external audio processordevice.
 14. A hearing device according to claim 1, wherein I) theparameter measuring circuitry comprises current measuring circuitry, thecontrolled signal includes a current signal, the predefinedcharacteristics include a current of predefined magnitude correspondingto a stimulation current level for a specific frequency for the user,and the measured quantity value is the transmitter coil current and/orthe external audio processor device current; or II) the parametermeasuring circuitry comprises voltage measuring circuitry, thecontrolled signal includes a voltage, the predefined characteristicsinclude a voltage generating a current of predefined magnitudecorresponding to a stimulation current level for a specific frequencyfor the user, and the measured quantity value is the voltage across thetransmitter coil and/or voltage across the external audio processordevice.